OK, so I received this amp today. Someone had it out at a garage sale, claimed it worked. ?? I received it an opened the cover to visually inspect the board and components before I just b+ the amp. It is very old, and condition is eh.
any ideas on the burnt resistors and spot on the board if it's visible in the picture.
any ideas on the burnt resistors and spot on the board if it's visible in the picture.Attachments
All outputs in both channels, all source resistors in both channels, many surface mount resistors of various values will need to be replaced. If you've never replaced the transistors on the MEHSA insulators, that adds to the complexity.
I have Perry on the 1001bd's u helped me with. I quest you have seen this before. I didn't even try to power it up. Maybe cheaper to send it off?
It won't be cheaper to send it off unless you find someone to offer free labor and can get free shipping. If you want to send it to someone, seankane may do it. I don't take in any repairs that have to be shipped to me.
i think i can handle most or all of this? it is a lot of time, testing all of those smd's, no scope, the rails and resistors i can handle. even the smd, just go through and test all the burnt ones or corner to corner? All of them. Where should i start, If i choose that route?
Desolder one leg of all remaining source resistors and the gate leg of all audio FETs.
Measure the resistance of all of the SMD resistors connected to the gates and source resistors. Mark all (red sharpie) that appear out of tolerance.
The most important thing is not to do any damage. If you damage the pads, it will make it harder to repair and will make it much more expensive to have it repaired if you cannot repair it.
Measure the resistance of all of the SMD resistors connected to the gates and source resistors. Mark all (red sharpie) that appear out of tolerance.
The most important thing is not to do any damage. If you damage the pads, it will make it harder to repair and will make it much more expensive to have it repaired if you cannot repair it.
those resistors are 0.1Ohm and 5% tolerance, are they 1watt or 2? ill also need to order the driver transistors MPN A06, A56, just correct me if i am wrong anywhere perry please. What audio FETs output transisors should i use? There are a few in here, IRF938D, IRF964, IRF640
Outputs are supposed to be IRF640s and IRF9640s.
You'll need to order the drivers and all of the various SMD parts.
Attached is a layout of a similar amp. The layout is slightly different but I think the designations are the same. Plan on replacing all highlighted plus any that you find out of tolerance.
The source resistors are 2 watt.
You'll need to order the drivers and all of the various SMD parts.
Attached is a layout of a similar amp. The layout is slightly different but I think the designations are the same. Plan on replacing all highlighted plus any that you find out of tolerance.
The source resistors are 2 watt.
Most of the audio transistors were either badly repaired or heated so badly they were almost separated from the rail already. So I lifted all of them being ill replace all of them anyway. Most of the and I tested even the burnt ones are still within tolerance.this is where I'm at.
Attachments
I just noticed this amp says Power800aII on the heatsink is that any different than the punch series amplifiers?
If your order didn't already ship I would call them ..
For the 800a2 amp you want IRF640'S not IRF640N someone correct me if I'm wrong but I believe the 640N will give you problems when used in this amp along with other Rockford Amps
For the 800a2 amp you want IRF640'S not IRF640N someone correct me if I'm wrong but I believe the 640N will give you problems when used in this amp along with other Rockford Amps
I would also recommend the non-N version of the output transistors.
You don't need 0.5% tolerance 20k resistors. They are likely more expensive.
Punch vs power is minimal but may be 12dB vs 24dB crossovers and similar features. I'm sure that others here could be more specific.
You wrote:
Most of the and I tested even the burnt ones are still within tolerance.
Something is missing.
You don't need 0.5% tolerance 20k resistors. They are likely more expensive.
Punch vs power is minimal but may be 12dB vs 24dB crossovers and similar features. I'm sure that others here could be more specific.
You wrote:
Most of the and I tested even the burnt ones are still within tolerance.
Something is missing.
I was writing i tested most of the SMD Resistors and a few are out, ill be replacing all on the sheet you sent me just for good measure anyway. Thanks everyone for the help on the parts, i ordered the correct ones today. I 'll just return the other ones, the .5 will work ok thought, It just means they are more accurate correct? it will only be +-.5? If so i may just use and keep them, i think they were way more expensive.
The tighter tolerance is OK. When ordering parts, it's good to get extras. Tight tolerance parts may prevent you (or anyone) from ordering extras (plenty of extras for cheap parts).
Shipping will likely be more than it's worth to return the parts. The IRF640N is used in some class D amps so they be useful later.
Shipping will likely be more than it's worth to return the parts. The IRF640N is used in some class D amps so they be useful later.
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