u/I_-AM-ARNAV

Saw this today.

What do you guys use as a GPU support?

Monitor started dying a year ago. So I got a similar second hand one. That's working fine but I decided to take a look at this one too. I thought it was the polarizer but the LCD itself is dead. The polarizer, the rear diffuser and the panel- all 3 are bad. The black markson the bottom are from polarizer. The cat shaped things are the LCD panel. The weird marks around hp is the rear diffuser.

It's a honda em650. Red part is where the breather pipe comes out off. I'm unable to understand how this is supposed to vent air. Shop Manual doesn't say anything about this part.

Hi, maybe you recognise me allready by the amount of posts I have made:)

My honda em650 is burning a lot of oil, leaking it too. It leaked almost 150 ml oil out. when it takes like 350 ml total.

Took it all apart and I would appreciate advice (pictures attached) regarding how is the breather even supposed to work in thsi case? Pics 3 and 4 is where the breather pipe was, got brittle and broke when taking it apart.

Took apart the piston and everything, to my eye the sleeve seems okay. No heavy signs of wear, no nail catching on the cylinder. But on the piston i do see wear on sides. Rings weren't stuck tho. They were free. No carbon. Cam and cam lobes seem fine too.

So.. it's the pcv / breather causing all the burning oil? Or am I wrong and piston is worn to the point that I will lead to oil entering combustion chamber? Or something to do with valves?

This is my first engine rebuild/ repair so I'll appreciate all the advicd you have.

Thanks!

​

I’m repairing a Sony MHC-GN100D mini hi-fi system and have run into one of the most mind boggling faults I’ve seen. I’ve been debugging this for hours (actually days) and would really appreciate a second set of eyes.

For context: a few front panel buttons had not been working(they died together in 1 night) for around 4 years, but since they weren’t used often, I never bothered fixing it.

A few days ago, more buttons suddenly stopped working overnight --specifically Groove, Effect, and Surround Speaker Mode, which I actually need since.

Looking at the service manual/schematics, the front panel buttons are divided into 3 separate key matrix / resistor ladder lines:

KEY0

KEY1

KEY2

The buttons that were dead for 4 years belonged to KEY2, and the recently failed Groove/Effect/etc buttons were on KEY1.

After tracing the circuit and measuring components, I found two 1.5kΩ resistors that had drifted way out of spec:

R961 (KEY2) - measured 5.2kΩ

R840 (KEY1) - measured 8.9kΩ

So I replaced both with fresh 1.5kΩ resistors.(Yes, resistors are a  symptom not a cause)

After replacement:

KEY2 came completely back to life (buttons dead for years now worked perfectly along with already working buttons)

BUT, everything on KEY0 and KEY1 went completely dead

Even stranger, the Power button also stopped working --and it is not part of any of these key matrices, it goes separately to the main board.

SO I assumed I may have shorted something, So I started reverting changes.

When I removed the resistor replacement on KEY2 (R961), KEY0 KEY1worked again

But obviously all the buttons, on key 2, after r961 died. Rest worked. Then I tested and checked thrice.

The moment I reinstall the correct 1.5kΩ resistor on KEY2 (R961):

KEY0 , KEY1 ,Power button dies. Only KEY2 works properly

I do not see any capacitors or other components around the key matrix that could be causing partial or full shorting to ground. Because it is just resistors to ground. No capacitors

What I’ve already checked:

Solder joints, No solder bridges, Correct resistor values confirmed with multimeter,Correct resistor placement confirmed against schematic,Checked continuity of traces,Checked all individual switches for shorts, Checked all resistor ladders on each key line, Checked surrounding components

Schematics/service manual:

[Sony MHC-GN100D Service Manual](https://www.manualslib.com/manual/954801/Sony-Hcd-Gn100d.html?utm_source=chatgpt.com)

Would really appreciate any ideas because I feel like I’m losing my mind on this one. and possibly ignoring something very simple?

PS. Forgot to take the voltage measurements on key 012 after putting R961 in. i will update that soon.

Attached: resistors I'm referring to.

 

Sony MHC-GN100D weird front panel key matrix issue --replacing bad resistor causes ALL buttons to die?

I’m repairing a Sony MHC-GN100D mini hi-fi system and have run into one of the most mind boggling faults I’ve seen. I’ve been debugging this for hours (actually days) and would really appreciate a second set of eyes.

For context: a few front panel buttons had not been working(they died together in 1 night) for around 4 years, but since they weren’t used often, I never bothered fixing it.

A few days ago, more buttons suddenly stopped working overnight --specifically Groove, Effect, and Surround Speaker Mode, which I actually need since.

Looking at the service manual/schematics, the front panel buttons are divided into 3 separate key matrix / resistor ladder lines:

KEY0

KEY1

KEY2

The buttons that were dead for 4 years belonged to KEY2, and the recently failed Groove/Effect/etc buttons were on KEY1.

After tracing the circuit and measuring components, I found two 1.5kΩ resistors that had drifted way out of spec:

R961 (KEY2) - measured 5.2kΩ

R840 (KEY1) - measured 8.9kΩ

So I replaced both with fresh 1.5kΩ resistors.(Yes, resistors are a  symptom not a cause)

After replacement:

KEY2 came completely back to life (buttons dead for years now worked perfectly along with already working buttons)

BUT, everything on KEY0 and KEY1 went completely dead

Even stranger, the Power button also stopped working --and it is not part of any of these key matrices, it goes separately to the main board.

SO I assumed I may have shorted something, So I started reverting changes.

When I removed the resistor replacement on KEY2 (R961), KEY0 KEY1worked again

But obviously all the buttons, on key 2, after r961 died. Rest worked. Then I tested and checked thrice.

The moment I reinstall the correct 1.5kΩ resistor on KEY2 (R961):

KEY0 , KEY1 ,Power button dies. Only KEY2 works properly

I do not see any capacitors or other components around the key matrix that could be causing partial or full shorting to ground. Because it is just resistors to ground. No capacitors

What I’ve already checked:

Solder joints, No solder bridges, Correct resistor values confirmed with multimeter,Correct resistor placement confirmed against schematic,Checked continuity of traces,Checked all individual switches for shorts, Checked all resistor ladders on each key line, Checked surrounding components

Schematics/service manual:

Sony MHC-GN100D Service Manual

Would really appreciate any ideas because I feel like I’m losing my mind on this one. and possibly ignoring something very simple?

PS. Forgot to take the voltage measurements on key 012 after putting R961 in. i will update that soon.