Pioneer SX-950 wont come out of protection

[1MEGΩ]

Is there a reference that I can look to for the transistors values ?
I take the readings but I dont know what is "normal".
I dont see them in the service manual

The numbers you show in this photo are normal. .5xx to .6xx and some can be .4xx

15415547654151558066796046245830.jpg

 

[petehall347]

2sc1628 appears shorted C to E

 

[CavScout]

That reading was in fact 0.00

Consensus ?

Is that shorted ?

 

[Watthour]

If tested on a 4000 terra-ohm scale, it might be a question. However, if tested on a diode/junction test scale, it's very likely shorted.

 

[petehall347]

try with your meter set on 200 ohm scale .

 

[CavScout]

I am using a fluke 101 which has an automatic feature.
Is that accurate to the point that would indicate those transistors are shorted ?

 

[Watthour]

It appears that the 101 does not include any feature which allows the range to be locked in or selected, with full-time auto-anging only. That can make it a little tricky to get very finite measurements sometimes.

 

[1MEGΩ]

I am using a fluke 101 which has an automatic feature.
Is that accurate to the point that would indicate those transistors are shorted ?

Just select Ω and do not press the yellow button for diode test. Give us the reading again across the emitter and the collector.

 

[CavScout]

For Q7 across E C reads .3 ohms

For Q1 across E C reads O.L
For Q3 across E C reads O.L

in fact, no activity at all on the ohm setting for Q1 and Q3 for any of the leads

 

[rcs16]

sounds like Q7 is toasted, always measure device leads switching probe polarities to test semiconductor junctions
Try the diode function to measure known good parts so you can get familiar with your DMM

 

[CavScout]

If Q7 Is bad does mouser.ca sell an equivalent? I tried searching that part number and it did not come up ?

 

[petehall347]

original 2sc1628

sub .. KSC3503estu

 

[rcs16]

watch out for the pinout
2sc1628 is EBC
KSC3503 is ECB

 

[CavScout]

When I search that part number it gives me a few options. Not sure which on to choose

 

[Watthour]

Look at the specs for a KSC2690AY. Add a 6043BG heat sink and it should outperform the 2SC1628. Pinout is still different, however.

 

[1MEGΩ]

When I search that part number it gives me a few options. Not sure which on to choose

Watthour is correct. When searching Mouser, it's best to put the Mouser part number in the search bar.
This is the transistor you need to order from Mouser. 512-KSC3503DSTU
The 512-KSC3503ESTU is obsolete.
512-KSC2690DSTU transistor
532-6043BG heat sink

 

[CavScout]

This is the transistor you need to order from Mouser. 512-KSC3503DSTU
The 512-KSC3503ESTU is obsolete.

Thanks , will do

 

[CavScout]

Still waiting for the new transistor to arrive.....

 

[1MEGΩ]

Still waiting for the new transistor to arrive.....

What's up with the delivery? Are they shipping it via Stagecoach?

 

[rcs16]

I get 2 day shipments from both Mouser and digi-key. Always order at least $100 to get free courier shipping, duties includes. fantastic service, without fail, check with them wants up.