Jfet is in the off state is closed between source and drain as though you would check it out of circuit.
power. LED 450 Power led is of course lit and is brighter that the other 2 lit LED407 and 406 and the power LED is .1 ov a volt biased higher than the other 2 therefore making the power LED 450 brighter this may be normal never noticed it before though
power. LED 450 Power led is of course lit and is brighter that the other 2 lit LED407 and 406 and the power LED is .1 ov a volt biased higher than the other 2 therefore making the power LED 450 brighter this may be normal never noticed it before though
The operating voltages Pin1 and 8 on the ic's ne5532 are the one between the 2 electrolytic s up by the Jfet is 15.4 volts and the ones to the left and the right below the amp gain control is 36.7 volts. the ic's on the right and left of the db gain jump strip are both 36.7 as well. low power supply wacky over there on that side of the board? Resistors or transistors or something I can check feeding them?
The power supply pins for the NE5532 are 4 and 8, not 1 and 8. Do you have both positive and negative voltage on it?
I'm trying to get some more information on a similar amp. It may help in troubleshooting this amp.
I'm trying to get some more information on a similar amp. It may help in troubleshooting this amp.
Measure the voltage on them individually. You should have positive and negative 15v so it would have been 30v across them.
Measure the voltage on them individually. You should have positive and negative 15v so it would have been 30v across them.
What should I use on the boar as a reference point for doing the individually a component on the board as a marker as a reference point? Because when use use the term rail which was an old English reference point when I studied Marine electronics in the 70's I get lost. Sorry for my ignorance
What should I use on the boar as a reference point for doing the individually a component on the board as a marker as a reference point? Because when use use the term rail which was an old English reference point when I studied Marine electronics in the 70's I get lost. Sorry for my ignorance
Where is that voltage derived from on the power supply as can I might trace it from that point to power those ics that I may trace it down that way if they are off. I know wish full thinking but you have to be in this trade. I can't wait for My dvd to come FROM YOU as I love to learn new things and never stop learning in this trade. Thanks Perry for all help and lord it been a lot I THINK i HAVE THE LONGEST THREAD IN THE HISTORY OF YOUR FORUM.
Which supply is missing, negative 15 or positive 15?
I think the longest thread for a repair that I helped with was likely for an MTX7801. It was about double this one.
After you get the DVD, we'll see how much you want to learn. I'm still waiting on someone to read 100% of the material. I'm beginning to doubt that it's ever going to happen.
I think the longest thread for a repair that I helped with was likely for an MTX7801. It was about double this one.
After you get the DVD, we'll see how much you want to learn. I'm still waiting on someone to read 100% of the material. I'm beginning to doubt that it's ever going to happen.
Well I took marine electronics worked in the marine electronics for 5 years back when most of the gear on the vessels were vaccum tubes an just changing to transistors and you had limited time to get the radars and Loran C and Decca plus radar ship to shore phones and auto pilots working as you had to make the sailing time or the skippers would take you with your tool box and the shirt on your back for 2 weeks and we all got a dose of that, a sort of baptism to the fishing industry electronics. Then the co owner got the Radio Shack franchise and got the repair center depot and was recruted to do the repairs for radiodhack everything east of Montreal and another tech and was paid by the item and flat rate fee for Tandy corp of Canada who owned Radio Shack in Canada. Now that was learning in a hurry or starve and 14 hr days. Got that going and staff and trained after I learned the product. We then opened up a office eguipment supply company and was expexted to learn typewriters including IBM ball Selectric typewriters old key style and electronic just coming onto the market and juggled both service of consumer electronics and Office Equipment. We was into digital cash register and bond copiers so I lived in the books and classroom on course and work night and weekends to keep it all running in the service of both and then radio shack introduce the computers and they worked that line into the office end and had a 2 week crash course at Tandy In Barrie Ontario on them as we had them in publishing company that did three news papers and offices and consumers so the course was very intensive and introduced to primitive digital in a big way. Back in the day of the 8 inch floppy disk and black and white monitors Thank god i didn't have to get into the software or program writing end. I ran that and was senior tech for both departments so was on the toad and in the shop at night. Did that and grossed the highest sales in Canada of $ 500,000 and that was not the office end. I kept that up for 10 years and had 3 Radio Shack service techs and trained them from trade schools and 2 from office equipment trade schools for office equipment and was a working service manager for both departments and customer relations of the service end.
I burnt out and had to get into something less mental and more physical too much stress so a any ex employee gave my resume to a refrigeration company and the controls and monitoring was all going electronics so I had an interview and said he would train me and get my papers in appliance repair and then Journeymen papers in commercial refrigeration so I took it and loved it no stress or allot less than what I was used too. I actually had someone train me and not learning myself it was great. He was in domestic but her was air force trained in commercial refrigeration trained and wanted to work his business in that direction down the road. In 6 months I was trained and he was on his first vacation in 10 years as me andy wife moved to his bussiness from his home and looked after his 4 kids and our 2 for 2 weeks as they went to Ontario and 2 man was now 1 man and when a deepfreezer or fridge went down you went as lose of food was not exceptable and order parts and take service calls and plan them and keep the paper work and money looked after now that was long hours as he had a large clientele.
After 2 years we got into convince stores and hotels and store and heating etc and i trained night as he couldn't loose me for 7 weeks and write my 4 block exmas and acummulate 2000 hrs and study while i was working and write the next block as was accumulating my hours. and be on call and building a big new building in Bridgewater as we out grown the home operation in 2 years and bought a house and renovated it in a comercial zone and in 5 we had a new building built behind the old one and the old one torn down. we had 4 trucks on the raod and the owner was of the road and in the ofice and selling HVAC systems and was into small fish plants and malls Micheline, Reefer trucks and I had my Journeymen papers in refigeration and picking techs that went to refrigeration trade scholl and was hiring on my recommendations from taking them on the truck with me and resume and was woking on 40<00 ton Icemachines for ice plants that sold ice banks of them all abke to produce that much in 24 hours I was out night to 3 in the morning from seven that day depending when the calls cam in as I was resposible to keep the plants and reefer with frozen refers of rubber for Micheline or anything large or grocery store or malls running and now had 2 burner men and 2 full time installers as I couldn't install any more and keep the refrigeration running and when we left we had 2 sales men a stockroom and service planner man a secretary and a girl just to work the phones, Until mt back went out because of lack of help with heavy equipment and spent working off of steroids and pain killer cocktail injections to keep me going as being off wasn;t an option until i went totally down and spent 10 weeks in rehab for my back, and was told my day in that trade was over by the rehab specialist so that is how I opened my own little electronic shop and work when I can and stay small.
So I may shock you in doing your whole DVD for the 1st time...lol
I burnt out and had to get into something less mental and more physical too much stress so a any ex employee gave my resume to a refrigeration company and the controls and monitoring was all going electronics so I had an interview and said he would train me and get my papers in appliance repair and then Journeymen papers in commercial refrigeration so I took it and loved it no stress or allot less than what I was used too. I actually had someone train me and not learning myself it was great. He was in domestic but her was air force trained in commercial refrigeration trained and wanted to work his business in that direction down the road. In 6 months I was trained and he was on his first vacation in 10 years as me andy wife moved to his bussiness from his home and looked after his 4 kids and our 2 for 2 weeks as they went to Ontario and 2 man was now 1 man and when a deepfreezer or fridge went down you went as lose of food was not exceptable and order parts and take service calls and plan them and keep the paper work and money looked after now that was long hours as he had a large clientele.
After 2 years we got into convince stores and hotels and store and heating etc and i trained night as he couldn't loose me for 7 weeks and write my 4 block exmas and acummulate 2000 hrs and study while i was working and write the next block as was accumulating my hours. and be on call and building a big new building in Bridgewater as we out grown the home operation in 2 years and bought a house and renovated it in a comercial zone and in 5 we had a new building built behind the old one and the old one torn down. we had 4 trucks on the raod and the owner was of the road and in the ofice and selling HVAC systems and was into small fish plants and malls Micheline, Reefer trucks and I had my Journeymen papers in refigeration and picking techs that went to refrigeration trade scholl and was hiring on my recommendations from taking them on the truck with me and resume and was woking on 40<00 ton Icemachines for ice plants that sold ice banks of them all abke to produce that much in 24 hours I was out night to 3 in the morning from seven that day depending when the calls cam in as I was resposible to keep the plants and reefer with frozen refers of rubber for Micheline or anything large or grocery store or malls running and now had 2 burner men and 2 full time installers as I couldn't install any more and keep the refrigeration running and when we left we had 2 sales men a stockroom and service planner man a secretary and a girl just to work the phones, Until mt back went out because of lack of help with heavy equipment and spent working off of steroids and pain killer cocktail injections to keep me going as being off wasn;t an option until i went totally down and spent 10 weeks in rehab for my back, and was told my day in that trade was over by the rehab specialist so that is how I opened my own little electronic shop and work when I can and stay small.
So I may shock you in doing your whole DVD for the 1st time...lol
Sorry Perry I never told anybody and it just came pouring out I know this was not the forum for it or place or time as I just wanted to tell you I wasn't wasting your time and I would do your DVD and all of it and it all came out.
Sorry about that. I know the grammar is poor and spelling is off not bad for a guy who is partially dyslexic
Sorry about that. I know the grammar is poor and spelling is off not bad for a guy who is partially dyslexic
neither is totally missing the one by the jfet is pin4 5.6volts pin8 8.1volts
the other ones i checked this morning are pin4 12.5 v and pin8 24.3 v
the other ones i checked this morning are pin4 12.5 v and pin8 24.3 v
The low voltage source is the small yellow transformer near the speaker terminals. See if you can determine why the magnitude of the positive and negative voltages isn't equal. It seems like the center tap
if the tansformer checks and rings good and the magnitude is the same with seconday unhooked. is there a resistor bleeding to ground or changed it down or an ic leaking to ground? Is there resistor in that circuit and values for them if I need them?
Okay Perry will do. Thank you for that picture sometimes is worth a thousand words or diagram of a section.
We used to draw our own up in pencil on circuits for boards with no literature or schematics with the values and voltages of working sets of a section to have reference material for the next tech to use. Are you old enough Perry to remember those days?
Our switching power supplies back then on dc vessels scallop draggers and inshore boats was developed by Marconi and was comprised of a DC motor with double armatures on a shaft and 2 sets of fields winding or more depending frequency and a vaccum tube sub board to do what they are doing on car amps with only fets and toroidal transformer. The dc vonverter boxes were 2 feet long a ft high and wide and that was consider state of the art for DC vessels to run Our high current gear before the Fets.
We used to draw our own up in pencil on circuits for boards with no literature or schematics with the values and voltages of working sets of a section to have reference material for the next tech to use. Are you old enough Perry to remember those days?
Our switching power supplies back then on dc vessels scallop draggers and inshore boats was developed by Marconi and was comprised of a DC motor with double armatures on a shaft and 2 sets of fields winding or more depending frequency and a vaccum tube sub board to do what they are doing on car amps with only fets and toroidal transformer. The dc vonverter boxes were 2 feet long a ft high and wide and that was consider state of the art for DC vessels to run Our high current gear before the Fets.
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