Threshold 400a

[Rolexmonger]

Hello. I have an early non-cascode 400A, serial number A7801304. I sold it recently but it came back to me. In the process I discovered that there are issues I never knew about. For eg. that it had a meltdown before I bought it almost 15 years ago. It served me well, but after all that I have been through trying to get rid of it, I am now fed up and want to restore it to original running specs, i.e HOT! It appears that whoever initially fixed the blowup got scared it would happen again and so biased it coolly, but I would prefer that it get biased HOT again. A whole side has resistors that are grey, while the other side has original brown ones. I repalced 4 transistors recently due to an incident. Now I would just like to restore it, and need someone in the Toronto area to do the work without raping my wallet. The coloured plastic readout on the front came off during transit, and the would be buyer glued it on crookedly and there is some glue on it, but it is not the kind of glue that cannot be removed, plus it is on crookedly. I wish that he had just left it alone. How do I take off the faceplate and work on it at the same time without damaging anything? I will used silicone glue unless someone else has a better idea. Please give me any suggestions or help that you can give.

[audiopro]

I can help you out with it. Have two on the go right now.
email or PM me if you're interested. I'm in Hamilton.

[roddyama]

Have a read through the "Repair question re: threshold 400a" thread.

[Babowana]

Hi, Rodd Yama****a

Long time no see. How you doing?

[barchetta]

Originally posted by Rolexmonger
Hello. I have an early non-cascode 400A, serial number A7801304. I sold it recently but it came back to me. In the process I discovered that there are issues I never knew about. For eg. that it had a meltdown before I bought it almost 15 years ago. It served me well, but after all that I have been through trying to get rid of it, I am now fed up and want to restore it to original running specs, i.e HOT! It appears that whoever initially fixed the blowup got scared it would happen again and so biased it coolly, but I would prefer that it get biased HOT again.
SNIP.

Well; now you know why I offered you $300.00.. Even though you weren't very nice about my offer I hope my thread helps you.

Ill be honest with you.. if you dont know how to fix that meter panel I dont know how you are going to do the rest... but out of the kindness of my heart; to remove the panel you must remove the whole front plate. It sounds hard but its the 4 bolts on the front.. try to not scratch them.

Then work a razor blade slowly around the panel.. DO NOT try and remove the plexiglass front shield.. remove the panel from the red plexi.. work the blade around until its free. then get some nice silcone glue and glue it back straight. But your buyer said the meter isnt working.. so you might want to check that first.

I am assuming the led's are crooked and the panel in front is straight.. if the panel in front is crooked its gonna suck.. reason being is they used a very strong glue at the factory.. and also; if you scratch it with a razor you might see it... I hope its just the LED's that are crooked for your sake.

[Rolexmonger]

No, everything was straight, and not only that, everything was also working just fine when I had the amp. It came back with the plexiglass crooked. I wish that he had just left it alone. I have not bothered to turn it on, and I am not going to either. With all that I have learned about it, I am leaving it alone until somebody qulaified has a go at it. Thank you for your help.

[roddyama]

Originally posted by Babowana
Hi, Rodd Yama****a

Long time no see. How you doing?

Hi Babowana,

...been pretty busy. I pop online when I can and have posted a few times of late.

[RetroAudio]

Thanks for bringing it to our attention Rolex. It might be helpful to all of us somehow in the future. Deals can be good but can go bad too. Btw, your emails are turned off.

[johndi]

I was reading the info on burnt out leds but mine I believe are burnt for another reason that I do not know.

I purchased the amp used and the led's didnt work. The owner said the led's worked when he put the amp away but when he took out about 10 or so years later the did not work. Any suggestions on what might cause this?

Thanks in advance
John

[barchetta]

Yeah replace all the caps on the LED board. Assuming you checked the leads to power first. The caps are about the only thing that can go wrong on that board... and time is the culprit!