Hey I have been working on this punch 250a2. I got with a severely destroyed ps. Anyway I replaced all ps mosfets and driver transistors powers on nicely and idles good. But I what I just realized what else was missing is the HP/FULL/LP switch. It appears to be broken off. Is there anything I can do or any kind of replacement out there? Also one last question, I have a parts board 200a4 can I snag one of those off that board and instal on this 250a2? Thanks guys!
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It looks like it may fit I'm going to buy more desolder braid after I get off work. I hope it works out fine. Also what I noticed was none of the output transistors were shorted when the power supply was blown. Why's that? Both channels emit sound no DC on any of the channels though.
The power supply can fail without the outputs shorting.
If you're going to do this type of work, you need to buy a desoldering pump. I'd recommend the Edsyn DS-017 (buying direct from Edsyn to avoid counterfeits).
If you're going to do this type of work, you need to buy a desoldering pump. I'd recommend the Edsyn DS-017 (buying direct from Edsyn to avoid counterfeits).
Okay so installing that switch did nothing really. Still have static on the right channel and a pulsing static sound coming out the left. I can't figure out what's causing it. Any ideas?
Does anything change while rotating the bass boost or x-over pots?
Does anything change when you turn the gain pots up or down?
You said in an earlier post the channels both emitted sound? Was it the static sound or do they actually produce audio?
Does anything change when you turn the gain pots up or down?
You said in an earlier post the channels both emitted sound? Was it the static sound or do they actually produce audio?
When I turn up the bass boost or x-over knobs nothing changes. But when I the left gain up the right channel gets loud and plays loud staticky audio. And when I mess with the switch it goes from distorted audio (LP) and when I put it in full it plays audio one channel while the other is still pulsing staticky audio.
Yes it did but that was when I checked one channel I didn't fully test it till now i found these problems. I checked the traces near the op amps near the rcas I didn't find any open traces. Could it be LM337 & LM317 are bad?
Check your regulated voltages on pins 4 and 8 of the op-amps. They should be close in voltage as far as positive and negative. What you wouldn't want to see is like 5vdc+ on pin 4 and 15.50vdc- on pin 8 if that makes sense.
It almost sounds like the switch from the other amp may have been defective.
I would put my money on a bad gain pot or the selector switch. If you need parts I stock everything.
It almost sounds like the switch from the other amp may have been defective.
I would put my money on a bad gain pot or the selector switch. If you need parts I stock everything.
I replaced both of the 5k gain pots did nothing still the same. Ok so when turn up the left gain it makes the right channel that's able to play some Audio get loud and distorted. It really doesn't make sense to me. I have to keep both gains down for the right channel to be able to play ok audio after that it's very distorted. And the left channel is just distorted and pulses.
Which components are the op-amp? Is it LM337 & LM317? And no I don't have one but i do have a meter. Let me know what I can do next. I really want to fix this 250a2.
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