Hello all, I'm back with this amp again and it will not power up makes my power go into protect if I applie just the main power wires. It was a shorted transistor in the supply (D44VH4) one was bad so I removed it. It has been damage ever since I confused one of the speaker wires for the remote wire. I need help trying to figure out how to get this on again.
I got the power supply to turn on since one transistor was shorted plus a small glass diode. I used a 2N6488 transistor just one because that was the only good pnp transistor I had laying around. It gets hot (2N6488) so I'm guessing in this type of power supply all the transistors have to be the same for these problems to go away, right?
When it's powered on the transformer makes a loud whine and it's producing rail voltage for both sides so I installed a good pair of output fets it will not play. Also the open trace rail cap (I previsouly repaired) When I desoldered that trace the led light up a little brighter and when close it goes dim.
So far still no audio, loud whining transformer.
So far still no audio, loud whining transformer.
The 6488 is overheating because it's not well suited for switching duty.
I think you need to replace the power supply components (drivers, diodes and power transistors) to get the supply working properly. Then you can work on the output stage. When you do, replace the outputs in one channel at a time to limit confusion.
I think you need to replace the power supply components (drivers, diodes and power transistors) to get the supply working properly. Then you can work on the output stage. When you do, replace the outputs in one channel at a time to limit confusion.
What can I use for replacement for the D44V transistors? It's kinda hard since it's not a MOSFET based power supply. And what can I also use for the drivers?
I have successfully used the readily available D44VH10G as a replacement for the D44V in Punch 75's.
Yes. The D44VH10 was the transistor used in most of the older P45s.
The original D40D8 driver transistors are obsolete and very difficult to find. You can use MPSA06s or MPSW06s as replacements. I'd recommend mounting them under the board and applying heatsink compound between the A06s and the sink. If necessary, use a piece of foam weatherstripping between the board and the A06 to ensure that the A06 remains in contact with the sink. You can also use MPSW06/56s with a clip-on heatsink (56s when using them in the audio section of the amp). Of course, if you use the clip-on heatsink, you will leave the transistor on the top side of the board.
The diodes are 1N4148s.
The original D40D8 driver transistors are obsolete and very difficult to find. You can use MPSA06s or MPSW06s as replacements. I'd recommend mounting them under the board and applying heatsink compound between the A06s and the sink. If necessary, use a piece of foam weatherstripping between the board and the A06 to ensure that the A06 remains in contact with the sink. You can also use MPSW06/56s with a clip-on heatsink (56s when using them in the audio section of the amp). Of course, if you use the clip-on heatsink, you will leave the transistor on the top side of the board.
The diodes are 1N4148s.
Actually I have several sources for the D40D8, and they have tons of them. They are a little spendy at $7 each but still readily available. If you need them I guess you will have to pay the price. I have several in stock new and used.
Can someone please post up a good close up pic of the power supply of the punch 45? With drivers, and all. Also a schematic would great too. I have ordered the mentioned transistors and got 20 extras just incase I get another old Rockford amp like this. These are all my amps I'm collecting for my self and I have never heard a punch 45 so I'm trying by best to get it to work. Also I ordered outputs for this amp but future ele sent me IRF540N & 9540N I need the regular 540 & 9540. Can I return them? Or will these work in this amp?
I don't have the diagram.
What do you need to see in a photo that you can't see from the amp you have?
Do you have any of the original outputs that are not defective?
Unless you ordered 50 each of the N version outputs, it's probably not worth the cost of sending them back.
Don't expect much from this amp. Some believe they have magical powers but they're nothing special. That doesn't mean they're no good, it means that they're... nothing special.
What do you need to see in a photo that you can't see from the amp you have?
Do you have any of the original outputs that are not defective?
Unless you ordered 50 each of the N version outputs, it's probably not worth the cost of sending them back.
Don't expect much from this amp. Some believe they have magical powers but they're nothing special. That doesn't mean they're no good, it means that they're... nothing special.
I want to see how the original driver transistors are installed the originals are still good I took them thinking they were shorted but they aren't. I also replaced the small glass diode. And the test 6488 shorted because of heat while I checking the rest of the amp (did not have it clamped).
Ha I've heard people say they had these "pounding" there 15's which I don't believe.... I'm not expecting it to "pound" my speakers I just want to give it a listen on my Boston acoustics.
Both of the N channel outputs were shorted in both channels so i ordered IRF540 & 9540 to replace the TP3055A & TP12P05 outputs.
Ha I've heard people say they had these "pounding" there 15's which I don't believe.... I'm not expecting it to "pound" my speakers I just want to give it a listen on my Boston acoustics.
Both of the N channel outputs were shorted in both channels so i ordered IRF540 & 9540 to replace the TP3055A & TP12P05 outputs.
You are not likely to get much more than 100 watts out of the amp unless you run it below its rated load.
The square pad on the board is pin 1 for the drivers.
If the original power supply transistor shorted, you risk blowing another set of power supply transistors using the original drivers. When I first started repairing these amps, the drivers would look OK when checked but MANY times caused the power supply to fail very shortly after power was applied. Replacing The two diodes, the two drivers and the two D44VH10s was the only way to get the power supply to be reliable. If nothing else, install the MPSA06s temporarily until you get the amp working. After you get it working and see that it's reliable, then you can reinstall the original drivers.
The square pad on the board is pin 1 for the drivers.
If the original power supply transistor shorted, you risk blowing another set of power supply transistors using the original drivers. When I first started repairing these amps, the drivers would look OK when checked but MANY times caused the power supply to fail very shortly after power was applied. Replacing The two diodes, the two drivers and the two D44VH10s was the only way to get the power supply to be reliable. If nothing else, install the MPSA06s temporarily until you get the amp working. After you get it working and see that it's reliable, then you can reinstall the original drivers.
Not sure what the 45 is compared to the 150 non HD but here is the schematic for the 150, hand drawn.
https://sites.google.com/site/brandescm/home/projects/Punch150non-HD.pdf?attredirects=0&d=1
https://sites.google.com/site/brandescm/home/projects/Punch150non-HD.pdf?attredirects=0&d=1
I borrowed a 45 from a friend and took a couple of photos. It's the green board but the layout is either the same or very similar.
http://www.bcae1.com/temp/punch45/smaller.zip
http://www.bcae1.com/temp/punch45/smaller.zip
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