Ok, sorry about that, I posted my last question without reloading the page first. So do I remove the 640's and 9640's showing the low readings? input trans. ok?When there are multiple questions and/or multiple people helping, you need to ask questions in a way that makes it very clear what you're referring to. Either quote or take the time to ask the question more clearly.
ok, i'm not sure if you included text you didn't mean to coming from the previous test result in the line but I think I have it understood. Next time I will be sure to include the #'s on the circuit board. It would've made it a whole lot simpler. Please excuse my inexperience.Remove the ones that you were referring to that corresponded to the pieces of text that I copied and pasted from your post.
yes that's what I was referring to. I think I'm going to edit post #15 with the corresponding circuit numbers.It was in post 18.
Ok, thank you very much. I knew when I was logging the test like that it wasn't the right way so to speak. I am going to remove the 9640 at Q251 and the 640 at Q215 from the output sides. Now, i remove those 2 and test the others in the rows?To simplify...
Remove the transistors that read significantly less than 20 ohms from leg 1 to leg 2 or leg 1 to leg 3.
Already answered that one huh? They call me simple pat. I was hoping to change that here. Already ruined that chance!These appear to be defective. Remove them from the circuit and re-test the others:
1+2, other showing 1.3 legs 1+2
legs 1+2 reading .2
In the future, include the circuit board designation for each transistor (printed on the board next to the transistor -- Q251...).
I removed Q251. Q252 reads 2.06 across legs2+3 and climbs slow. Q253 reads 2.08 and climbs slow. Q254 reads 2.10 climbs slow. Q255 2.5 and climbs faster, Q256 reads same as Q255.Yes. Retest. It's likely that no others will read near 0 ohms.
Removed Q215. Q216 reads 3.0 and climbs. Q214 reads 2.1 and climbs slow. Q213 reads 2.8 climbs slow. Q212 reads 2.8 climbs slow. Q211 reads 2.8 climbs slow.
All were checked on legs 2+3.
Just so were on the same page, the power supply fets are Q17-Q24 (IRF3205's) right? Legs 2+3 on those were starting low around .3ohms but were climbing very slow. Then the meter would jump to 10ohms and drop very slow. I dont know what that means besides cheap meter.Were any of the power supply FETs blown in this amp?
Yes my meter reads OL when probes arent touchingThey are defective. If you read anything other than OL (or whatever your meter reads with the probes not touching anything) between leg 1 and the other legs, the FET is defective.
Oh boy! Wish me luck, gonna be a couple of days probably. Thanks for your help! I'll be back.As long as you don't get a constant low resistance, they're likely OK.
Reassemble the amp and clamp all transistors tightly to the heatsink. Insert a 15 amp fuse in the B+ line and see it the amp will produce clean audio.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
- Home
- General Interest
- Car Audio
- Help with Memphis 1000D's