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[Console Repair/Mod Center / Re: Turbo Express Potentiometers Adjustment]

VR500 on this unit is measuring -14V and not the normal -24V from C502.  This is with the screen plugged in.  Voltage of VR501 seems to be adjusted fine as caps are reading 4.82V

Obviously something is wrong with the VR500 measurement.  I cant seem to get it to change or adjust with adjustments to the VR500 potentiometer.  I did these measurements with the OEM power adapter.

[Console Repair/Mod Center / Turbo Express Potentiometers Adjustment]

Hi All,

Can someone give the proper directions for adjusting the VR500 and VR501 potentiometers?  I have an Express that will not work after cap replacement (I have done a few of these) and need the exact procedure.  I think there is a voltage issue on this board and it may have also blown the screen.  The screen tested fine on another working unit (my personal Express) and now does not work at all even when connecting to the known good Express.  Not a good day for retro repairs.

Questions:

1.) I have searched the forums and know that for VR500 I need to find the -24 volt reading by measuring the CC50 22uF 35v cap.  Do I just measure this from the cap black to positive red to negative and adjust the VR500 potentiometer until -24?
2.) For VR501 (4.5 volt) do I get the reading from CC502 4.7uF 50v?  What voltage should this be reading?
3.) Can I use batteries for this test or does it need to be the OEM plug?
4.) Does anyone on the forums sale used OEM screens?  Are their procedures at to attempt to repair a screen documented?  I definitely have a screen issue here as well after the recap.  It must blown something on the screen as the backlight still works. But no picture even on the known good unit.
5.) Can anyone with a broken or old board for parts sell me a L105 inductor from their old unit?  Mine broke in my personal Express and need to find a replacement.  This inductor is at L105 and is right by the headphone jack.

Thanks guys - CrazedBinary

[Console Repair/Mod Center / Re: Express Headphone Issue]

Additionally, I just tested the working part in the Express with the headphone issue.  It solved the issue.  Now I just need help finding the replacement part.

Just as an FYI the broken inductor/resistor seemed to be broken in half when I desoldered it like it had cracked down the middle.

Thanks in advance - Crazed

[Console Repair/Mod Center / Re: Express Headphone Issue]

OK I was able to get the part out of a working Express and below are the readings I found.  This was using my  DER EE DE-5000 LCR Meter in auto mode. 

1khz 0.562 ohms - resistor
10khz 0.805 ohms - resistor
100khz 1.350 uh - inductor (it picks it up as an inductor at 100khz)
100hz 0.56 ohms - resistor
120hz 0.57 ohms - resistor

I am trying to figure out is this is a resistor or an inductor and also what part to replace it with.  Is the eBay part mentioned earlier still a good bet?

Thanks all - Crazed

[Console Repair/Mod Center / Re: Express Headphone Issue]

Sorry that was meant to read:

@1khz 1.1-1.5 uh usually 1.2-1.3
@10khz 1.28 uh
@100hz 1uh
@120hz 1uh

I think LOL.

[Console Repair/Mod Center / Re: Express Headphone Issue]

Hi Keith -

I think the traces and jack are fine.  Pic attached for reference.  I desoldered it before attempting any work and it appears to be ok.  This particular inductor is testing differently on this Express compared to another.  I took reading from the "good one" still in circuit as I had to get it back to a friend.  Below are the readings I got.  Still learning inductance measuring so bear with my newbness.  Any help on sourcing this part would be great.

Inductance Measurements:
@1khz 1.1-1.5 mh usually 1.2-1.3
@10khz 1.28 mh
@100hz 1mh
@120hz 1mh

Resistance:
0.61 ohms

When using the "auto" part of the DE 5000 it identified the part as a resistor.  Not sure if that is correct.





Thanks - Crazed

[Console Repair/Mod Center / Re: Express Headphone Issue]

Unfortunately my Atlas can only do ESR/Cap measurement.  I was looking for an excuse to get an LCR meter anyway and went ahead and pulled the trigger on a DE-5000 to measure inductance etc... 

Do I need to desolder the working one to get an accurate reading?

[Console Repair/Mod Center / Re: Express Headphone Issue]

That is correct.  There is not continuity over this inductor.  It tests fine on the other Express. 

Better pic attached for reference as well.

Any idea on how to source a replacement?



Thanks all!
Crazed

[Console Repair/Mod Center / Express Headphone Issue]

Whats up.

I recently did a recap using a SMD kit from console 5.  Everything is back and running well except the headphones.  Loud buzzing and only one sound channel it seems.  I have two expresses right now and I was measuring caps and checking traces.  ESR and everything look good with the new caps. 

There is a small ceramic capacitor/resistor?? L105 that looks like it may be bad by the headphone jack.  I cant measure ESR from it.  Anyone know if this could cause the issue and if so what a good replacement is?  Pic Attached.

[Console Repair/Mod Center / Re: Turbo Express Turbo Buttons]

Thanks for the wonderful advice.  Any ideas on the turbo button repair?  My ears hurt now.  I dont use turbo but would like to restore this puppy.

[Console Repair/Mod Center / Turbo Express Turbo Buttons]

Whats up -

I recently recapped (all caps) and repaired some bad traces on an Express.  When I got the unit back together after good cleaning the I/II buttons were acting sporadic and the Turbo functions would not work at all.  At that point I looked on the control board and saw some corrosion. 

Cleaned up what I could (mmm fish) and did a similar repair as mentioned here:
http://nfggames.com/forum2/index.php?topic=4238.0

I did the same repair but without drilling the board.  Now the I/II buttons work much better but I still have no turbo functions.  When I turn on the turbo functions the buttons just stop working.  I may need to reroute these as well but wanted some advice from the experts first.

Thanks for any assistance -

Crazedbinary