just found this forum so big noob here. my amp only has sound through the hi channel but none through the bass. i did burned the amp couple months ago and try to repair it. i had my cousin replace some of the resistors and transistors that were brunt r cracked, but it still didnt work. i did search through the forum but didnt find nebody with the same problem. if u guys need me to post pictures i will, but the amp is still mount in my car. dont feel like taking it apart.
None of your links are working it seems, But I can tell you by the part number you replaced the power supply Fets, and there gate resistors.
This is a symptom repair you performed, I am fairly sure the sub channel is toast also. bass channel power supply's don't usually fail by themselves. They usually fail after the sub outputs are shorted.
So there was more wrong then was openly visible. PG lists a flat repair rate of $150.00 for this amp if your in the USA. The outputs are TIP-35 and TIP-36, you should check these out for shorted condition before trying to repair the power supply.
See if you can get your links to work, so I might see your previous work....
This is a symptom repair you performed, I am fairly sure the sub channel is toast also. bass channel power supply's don't usually fail by themselves. They usually fail after the sub outputs are shorted.
So there was more wrong then was openly visible. PG lists a flat repair rate of $150.00 for this amp if your in the USA. The outputs are TIP-35 and TIP-36, you should check these out for shorted condition before trying to repair the power supply.
See if you can get your links to work, so I might see your previous work....
OK lets get started...
Q9 thru Q16 are the four channel power supply mosfets. Your repair looks ro have worked to get the amp back running, but you said there were bad channels, could you give me more info like Rear channels maybe ?
If this is correct you must ohm out the outputs for the bad channels....LMK...Please tell me the Q numbers by the devices you replaced, so I can locate which power supply you repaired??? THX
Q9 thru Q16 are the four channel power supply mosfets. Your repair looks ro have worked to get the amp back running, but you said there were bad channels, could you give me more info like Rear channels maybe ?
If this is correct you must ohm out the outputs for the bad channels....LMK...Please tell me the Q numbers by the devices you replaced, so I can locate which power supply you repaired??? THX
Sounds like you have blown outputs in your sub channel. Ohm the TIP-35 and TIP-36 output . If one is bad they both will read bad. These should be numbered Q546, Q548 for the TIP-35, and Q547 and Q549 for the TIP-36 devices.
These might read shorted depending on how the amp failed. One thing for sure is that the sub channel failed first taking out the power supply.
A sure test is with the amp idled with power on, take a volt meter and read the voltage on the speaker terminals for the sub out. It will most likely be around 50 volts DC.. if the outputs are toast.
The Q's you replaced were the 4 Sub amp power supply fets, so yes the sub channel is bad most likely. The load yyou ran would have less to do with the faliure then the gain setups used on the amp.
These might read shorted depending on how the amp failed. One thing for sure is that the sub channel failed first taking out the power supply.
A sure test is with the amp idled with power on, take a volt meter and read the voltage on the speaker terminals for the sub out. It will most likely be around 50 volts DC.. if the outputs are toast.
The Q's you replaced were the 4 Sub amp power supply fets, so yes the sub channel is bad most likely. The load yyou ran would have less to do with the faliure then the gain setups used on the amp.
I would look at Q-534, 535, 537, and 538. these are your input pairs, and they most likely have been damaged by overloading and clipped drive. These cost less and are much smaller and are most likely the source of damage. < 2sa1266, and 2sc3198 are the device numbers in the input stage
If after replacing these your DC output does not drop closer to zero, then there are probably more damaged components in the channel.
There are 17 total transistors in the sub channel. Any one or more could be damaged. without real tech equipment and training to troubleshot these devices, your going to have trouble from here on out getting this issue resolved
This amp is configured using PG's hallmark Triple Darlington output stage. This means the 4 outputs are directly driven by two sets of drivers prior to the outputs. Any of these could be leaky and causing DC offset also. 8 transistors are in this stage total.
The remaining 5 transistors are mute bias pair as current sources for the input pairs, another pair as a stage after the input diff pairs., and a single transistor for bias control.
Not trying to be unkind but at this point you should consider seeking trained help in this section of the amp. My description alone should give anyone with tech training a lot of info to guide them through this amp. But without serious training, and experience this could be No Mans Land for many, strictly because of the training required to service this area.....I buy parts in bulk, so this channel would cost me maybe $5.00 to replace completely, but for the average person buying single quantity parts the price will most likely be around $20.00 to $35.00 for parts, plus the time involved.....I hope my info has been helpful...
If after replacing these your DC output does not drop closer to zero, then there are probably more damaged components in the channel.
There are 17 total transistors in the sub channel. Any one or more could be damaged. without real tech equipment and training to troubleshot these devices, your going to have trouble from here on out getting this issue resolved
This amp is configured using PG's hallmark Triple Darlington output stage. This means the 4 outputs are directly driven by two sets of drivers prior to the outputs. Any of these could be leaky and causing DC offset also. 8 transistors are in this stage total.
The remaining 5 transistors are mute bias pair as current sources for the input pairs, another pair as a stage after the input diff pairs., and a single transistor for bias control.
Not trying to be unkind but at this point you should consider seeking trained help in this section of the amp. My description alone should give anyone with tech training a lot of info to guide them through this amp. But without serious training, and experience this could be No Mans Land for many, strictly because of the training required to service this area.....I buy parts in bulk, so this channel would cost me maybe $5.00 to replace completely, but for the average person buying single quantity parts the price will most likely be around $20.00 to $35.00 for parts, plus the time involved.....I hope my info has been helpful...
http://www.findchips.com/avail
I use this link a lot, but for Asian transistors Pacific Coast Parts and or google the part numbers, oh theres also Ampslab online for some amp parts...
I use this link a lot, but for Asian transistors Pacific Coast Parts and or google the part numbers, oh theres also Ampslab online for some amp parts...
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