Yeah thought it had when it got that hot yesterday or day before within seconds and I mean hot to point of coating starting to melt. So not surprising. I think those ones you can pick up for 15 16 quid prob bit less. I'll have to measure the secondaries on the good one work out spec. Poss 300va maybe 5 amp 2 x 35v. Think it's on here somewhere I'll look through. Just guestimation.
It's very unlikely that you burned the transformer or else it would blow the fuse in the plug (you have a fuse in there don't you?) if you have a short or the mosfets in the wrong position that may explain your lack of voltage and the overheating of them (Voltage sag due to load) in that case I would remove the TO3 mosfets from the board and power it up without them to test power supply.
Your transformer (and mine) has a secondary of 42/0/42Vac (+/-55Vdc)
My bits are not here yet but they arrived in the UK last Friday (tracking supplied)
Your transformer (and mine) has a secondary of 42/0/42Vac (+/-55Vdc)
My bits are not here yet but they arrived in the UK last Friday (tracking supplied)
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Cor blimey still waiting same here mine also in UK for a week they must have an economy pile in the sorting office and just dump it there. Either that or a customs bill is coming.
Yep your right tranny okay but that module I'm to the point of stamping on it and out the window job. It just don't make any sense at all. I've checked re checked checked re checked bla bla and everything is correct and as it should be. At 30vac on variac the transformer just explodes into a radiator. 30vac!!!!!! Work that out fluffed if I can. The LED won't light up so something going on around the transistors there. But it all checks as should. All I can think of is I had to stretch the transistors legs sidewards to mount them so could of caused a break internally or the resistors all 0.5 watt instead of 1/4 watt plus all 2% so the tolerance has been tightened up by 3%. Could be that as I know these transistors can be well politely sensitive plus if not matched then again can cause problems. But the LED pur what's going on there? Blimey been nothing but a headache this module and it's not even a complicated circuit. Output okay but we have no power on the LED side and an overheating tranny gotta laugh aye. Or the tracks are too wide.
Anyhow hey ho.
Yep your right tranny okay but that module I'm to the point of stamping on it and out the window job. It just don't make any sense at all. I've checked re checked checked re checked bla bla and everything is correct and as it should be. At 30vac on variac the transformer just explodes into a radiator. 30vac!!!!!! Work that out fluffed if I can. The LED won't light up so something going on around the transistors there. But it all checks as should. All I can think of is I had to stretch the transistors legs sidewards to mount them so could of caused a break internally or the resistors all 0.5 watt instead of 1/4 watt plus all 2% so the tolerance has been tightened up by 3%. Could be that as I know these transistors can be well politely sensitive plus if not matched then again can cause problems. But the LED pur what's going on there? Blimey been nothing but a headache this module and it's not even a complicated circuit. Output okay but we have no power on the LED side and an overheating tranny gotta laugh aye. Or the tracks are too wide.
Anyhow hey ho.
Yes about 2v higher than otherside. But it always was slightly higher. So think the transformer is fine. I think the power is not getting through to the transistors hence no voltage on the led so the transformer is not discharging it’s voltage across the circuit hence it’s getting hot quickly as all voltage is being held at the transformer. That’s my analogy.
So could be shorts on transistors as I had to bend the legs sidewards quite a distance to get them to fit the wider tracks. All I can do is solder additional wire onto the legs of the ones I’ve not had to bend and solder in that way see what happens. Unfortunately I can’t keep it running long as it’s getting way too hot at 32vdc let alone ranking hit up to 240vac. So no readings possible at present plus explains why those resistors on this occasion started to fry.
So could be shorts on transistors as I had to bend the legs sidewards quite a distance to get them to fit the wider tracks. All I can do is solder additional wire onto the legs of the ones I’ve not had to bend and solder in that way see what happens. Unfortunately I can’t keep it running long as it’s getting way too hot at 32vdc let alone ranking hit up to 240vac. So no readings possible at present plus explains why those resistors on this occasion started to fry.
Or even easier...
Without the transformer connected to board check for shorts between the V- / ground / V+ even without removing anything.
Power supply arrived today, very impressed with the build quality (Nippon Chemi-Com 105c LXM 4x10000uF caps) not bad for 30 quid.
Now need to sort a chassis the amp doesn't fit in the charger case.
Without the transformer connected to board check for shorts between the V- / ground / V+ even without removing anything.
Power supply arrived today, very impressed with the build quality (Nippon Chemi-Com 105c LXM 4x10000uF caps) not bad for 30 quid.
Now need to sort a chassis the amp doesn't fit in the charger case.
Nice one pic be good. Oh deary me I’m on look out at moment on flea bay for broken unit so I can use the chassis. Keep putting an offer in for this particular one but not even coming back with a counteroffer makes you wonder why they even bother putting make offer on there.
Done all that had enough of removing testing etc it’s just one of those I don’t think your gonna troubleshoot the problem. I’ve gone as far as I can. Definitely a short somewhere but shorts don’t always reveal themselves. Like say transformer is fine with regards to output voltages. But I think for it to get that hot that quick it’s not discharging any voltage out which means the problem is on the board or there is a short in transformer. I could get two brand new boards made up cheapest found was 134 quid all in including postage. Single sided 2mm FR4 2oz tracks sealed and gold plated solder points. But do I wanna be spending that. I could make up another board but follow the exact size of all tracks no trying to modify it. Got a clad board left. But need a break from it or I will break it ha ha.
Still can’t grumble really over past couple years that’s the first time I’ve not been able to fix the problem. But then again it’s first time I’ve bothered with this type of circuitry.
But can’t remember who it was now but he said he had six of these fail and he could not find the problem. So must be some kind of design fault. That Maplin is more or less the same except a few alterations but bomb proof have you got any grenades worth a go see what end result would be ha ha lmao.
Done all that had enough of removing testing etc it’s just one of those I don’t think your gonna troubleshoot the problem. I’ve gone as far as I can. Definitely a short somewhere but shorts don’t always reveal themselves. Like say transformer is fine with regards to output voltages. But I think for it to get that hot that quick it’s not discharging any voltage out which means the problem is on the board or there is a short in transformer. I could get two brand new boards made up cheapest found was 134 quid all in including postage. Single sided 2mm FR4 2oz tracks sealed and gold plated solder points. But do I wanna be spending that. I could make up another board but follow the exact size of all tracks no trying to modify it. Got a clad board left. But need a break from it or I will break it ha ha.
Still can’t grumble really over past couple years that’s the first time I’ve not been able to fix the problem. But then again it’s first time I’ve bothered with this type of circuitry.
But can’t remember who it was now but he said he had six of these fail and he could not find the problem. So must be some kind of design fault. That Maplin is more or less the same except a few alterations but bomb proof have you got any grenades worth a go see what end result would be ha ha lmao.
Sorry no pics (yet)
I don't what wrong with me but I fell really tired for some reason or else I would offer to help you with that board (sent to me to give a go at fixing it) but I have to many things in my plate right now and on top of that a full time job.
About that someone that wasn't able to fix 6(?) of those board I find it hard to believe because at a last resort replacing all the components on the board is not more then 5 quid (without the power caps) and 30 minutes worth of labour.
Can only wish you good luck with your board(s).
I don't what wrong with me but I fell really tired for some reason or else I would offer to help you with that board (sent to me to give a go at fixing it) but I have to many things in my plate right now and on top of that a full time job.
About that someone that wasn't able to fix 6(?) of those board I find it hard to believe because at a last resort replacing all the components on the board is not more then 5 quid (without the power caps) and 30 minutes worth of labour.
Can only wish you good luck with your board(s).
Totally unrelated but me bits came. That psu board 5mm thick. Managed to get some sk42 heatsinks only 12 quid each bargain. 5mm thick bloody heavy for size.
Anyhow not related but just wanted to show off ha. I might change out those resistors get some better quality ones. Think there carbon film. Hard to tell don’t look metal film.
I’m going to draw out a new board for the unit but to exact size of original. Like said had to bend those legs on those transistors way too far apart sideways. Don’t think there meant to be forwards yeah not sidewards. Would not surprise me if I’ve not cracked the internal substrate in them.
Anyhow not related but just wanted to show off ha. I might change out those resistors get some better quality ones. Think there carbon film. Hard to tell don’t look metal film.
I’m going to draw out a new board for the unit but to exact size of original. Like said had to bend those legs on those transistors way too far apart sideways. Don’t think there meant to be forwards yeah not sidewards. Would not surprise me if I’ve not cracked the internal substrate in them.
Attachments
No not yet moved over to a repair job someone who did not know what they where doing.
So the Matrix M400 fully up and running including the VU meter and fan plus some other bits. Needed a break from that one was getting to frustrated. Re drawn the pcb correct size this time on the tracks so just need to do some tidying up on paint shop then do the new board. Start all over again. I was gonna just add jump wires on the old board where the tracks are missing but not sure if that will work properly be fine on valve gear but not sure if the transistors would like it. That’s easy option what do you think?
Plus gathering all parts for F5 gonna build my own cabinet for that.
So I’ll give this BK one more go and if the readings on the outputs are up the creek again I’ll give it up. As it makes no sense at all the other board bang on and considering there’s no difference between them except the new transistors but it was way out on output before I even put them in. So all it can be is there is a short on the tranny as it warms up well you could fry an egg on it.
So the Matrix M400 fully up and running including the VU meter and fan plus some other bits. Needed a break from that one was getting to frustrated. Re drawn the pcb correct size this time on the tracks so just need to do some tidying up on paint shop then do the new board. Start all over again. I was gonna just add jump wires on the old board where the tracks are missing but not sure if that will work properly be fine on valve gear but not sure if the transistors would like it. That’s easy option what do you think?
Plus gathering all parts for F5 gonna build my own cabinet for that.
So I’ll give this BK one more go and if the readings on the outputs are up the creek again I’ll give it up. As it makes no sense at all the other board bang on and considering there’s no difference between them except the new transistors but it was way out on output before I even put them in. So all it can be is there is a short on the tranny as it warms up well you could fry an egg on it.