Thread

Typical Video Board issue with all Mac SE versions and SE/30.

Typical Video Board issue with all Mac SE versions and SE/30. Troubleshooting 29 posts Oct 12, 2014 — Sep 1, 2019

#1 Sun, 12 Oct 2014 - 05:05

The 2N3904 goes bad.

Screen Shot 2014-10-11 at 11.59.36 PM.png

#2 Sun, 12 Oct 2014 - 05:53

In all my years I have never seen that part fail. But since its been over 20+ years, sooner or later it would have too fail. Nothing last forever.

#3 Sun, 12 Oct 2014 - 06:08

I just repaired 3 video boards.

also this site also talks about this issue.

Repair Macintosh SE/30

http://www.biwa.ne.jp/~shamada/fullmac/repairEng.html

(5) Troubles of the transistor Q1 on the video board. The video board is a small board where the CRT socket is soldered.

(5) If none of the above doesnt't work, replace the transistor Q1 (2N3904, NPN transistor) on the video board.

#4 Sun, 12 Oct 2014 - 06:23

Don't want to bring up old threads, but this part is what has gone bad in this guys Video board as well.

https://68kmla.org/forums/index.php?/topic/20541-se30-horizontal-sweep-linesstill/

Tekk

I got my hands on another video board, swapped them out, and it now works perfectly. Still haven't figured out what was wrong with the original video board; that's for another day.

#5 Sun, 12 Oct 2014 - 06:29

ok looks like its in DMS as well.

[SIZE=9pt]Symptoms: [/SIZE][SIZE=9pt]There is raster but no video display. The raster is very bright. Horizontal scan lines are visible.[/SIZE]

[SIZE=65pt]

[/SIZE]
[SIZE=9pt]Probable diagnosis: [/SIZE][SIZE=9pt]The problem is on the CRT socket board [/SIZE]

[SIZE=9pt]Solution: [/SIZE][SIZE=9pt]Check/replace the 2N 3904 transistor (NPN, 0.6A, 1/2 watt, TO-92) at board reference Qi. Depending on the board revision Q1 could either be on the left or on the right. Also see the prior entry. [/SIZE]

#6 Mon, 13 Oct 2014 - 22:34

Hi all, I'm a new member of this forum... Some days ago a friend of mine gave me a SE/30 he had kept in his garage for years. It had the same video issue described in this thread and no sound. I did a total recap of the logic board (and checked every capacitor) and got the sound again but not the video issue. Then I tried to replace the 2N3904 transistor, but no luck again.
I checked the resistors on the logic board and they seem to work as expected.
Any other clues? What should I try?

macse30.jpg.dd561ea546db0a9fd021c1685ec393b4.jpg

#7 Mon, 13 Oct 2014 - 22:48

in this case it looks like you have a botched UE8 on the mainboard. — probably cap goo'd up.

At the least you can hot air flow it off, clean it up … and flow it back on.

#8 Mon, 13 Oct 2014 - 23:09

LIttle more info:

from my post over on thinkclassic.org

https://www.thinkclassic.org/viewtopic.php?id=59

One of the biggest issues i have with the SE/30 is UE8, there is a cap right there and it leaks its OOze right on/in UE8, Sometimes the I/C goes bad because of this. Sometimes you can hot air flow off UE8, And flux&wick clean up the pads… get some fine grit sand paper and clean up the legs of UE8 and re attach it and it will work fine.

but sometimes you need a to replace it.

UE8 issues = No Video
UE8 issues = Video with lines (pin stripes)
UE8 issues = Can give you the same symptoms as a bad Video board ( on the back of the crt )

Here is the big one. and yes this has happen to me now 2 times.

UE8 issues = Depending on on what level of damage the cap goo has caused, And how the I/C has failed — can cause a No tone, No Boot! Yup!

I was surprised my self, I found this one by accident...

^^ one other cause for Pinstripes in your SE/30 Video ^^

Datalines 0-7 come from the VRAM.
Sometimes the via's can rot (via's right near UE8) that are datalines 0-7 coming from the VRAM.
So in this instance you have to run a patch wire from the correct pin of UE8 to the vram.

You can check what one is bad with the se/30 schematics and and multimeter and check for 000 ohms 0-7
and if you get one with no continuity, that is the line.

#9 Mon, 13 Oct 2014 - 23:55

thank you for your precious tips. Tomorrow I'm going to check UE8. In the case, what's the right replacement piece for UE8?

#10 Tue, 14 Oct 2014 - 01:25

[SIZE=10pt]±4-mA [/SIZE][SIZE=10pt]Output Drive at 5 V [/SIZE]

[SIZE=10pt]Low Input Current of 1 [/SIZE][SIZE=10pt]μA[/SIZE]

[SIZE=10pt]Max Synchronous Load
Direct Overriding Clear [/SIZE]

[SIZE=10pt]Parallel-to-Serial Conversion [/SIZE]

Screen Shot 2014-10-13 at 8.26.35 PM.png

http://www.mouser.com/Search/ProductDetail.aspx?R=SN74HC166AIDREPvirtualkey59500000virtualkey595-SN74HC166AIDREP

Techknight has one that he uses as well from digikey.

#11 Tue, 14 Oct 2014 - 01:26

LS = Low speed/power shottkey.

HC = High speed cmos.

HC will work in place of an LS, but will be a bit more power hungry.

#12 Tue, 14 Oct 2014 - 01:30

here is a LS part

Screen Shot 2014-10-13 at 8.33.27 PM.png

http://www.mouser.com/ProductDetail/Texas-Instruments/SN74LS166ADR/?qs=sGAEpiMZZMtsbn1GaJysl8drSYt3ukOhq0vGiHwZkh0%3d

#13 Tue, 14 Oct 2014 - 01:34

trying to figure out how much more power hungry.

#14 Tue, 14 Oct 2014 - 12:41

Would you definitely advice HC or LS to replace UE8?
In order to reduce shipping cost and time, I want to buy this IC from a local vendor (I'm from Italy). Is every 74LS166 (or the HC one) the same or I should check something before buying?

For instance, I've found these on ebay:

http://www.ebay.it/itm/INTEGRATO-74LS166-CONFEZIONE-DA-5-PEZZI-/270871407139?pt=Componenti_elettronici_attivi&hash=item3f1131aa23

Are these ok?

#15 Tue, 14 Oct 2014 - 13:00

Nope. They are SOIC SMD

#16 Tue, 14 Oct 2014 - 20:29

just you can buy ether or. people on this forum have bought the HC and it worked just fine. Mike just buys the LC version from Digi-key and it works out just fine as well. if it was me i would buy 10 at a time, and i guess i would choose what ever version was the best deal

they look like they are about 80 cents each.

Package / Case: SOIC-16 Logic Family: HC Logic Type: CMOS Number of Input Lines: 9 Propagation Delay Time: 150 ns, 30 ns, 26 ns Maximum Operating Temperature: + 85 C Minimum Operating Temperature: - 40 C Packaging: Reel Function: Shift Register Mounting Style: SMD/SMT

#17 Tue, 14 Oct 2014 - 20:41

hey mike what other 74 series SOIC-16 I/C's might work?

http://www.ebay.com/sch/i.html?_odkw=74LC166&_from=R40%7CR40%7CR40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.X74HC166&_nkw=74HC166&_sacat=0

there is a bunch of different 74 series I/C there on ebay some of them are pretty inexpensive.

#18 Tue, 14 Oct 2014 - 22:30

Well, I checked each UE8 pin for continuity and every line is ok. I removed it off the board, cleaned and reattached but the video issue is still here. So I suppose I have to replace it...

Is this lot a right choice in your opinion?

http://www.ebay.com/itm/5x-74HC166-SMD-HC166-Schieberegister-8-Bit-paral-SO16-/360415372474?pt=Bauteile&hash=item53ea6e24ba

#19 Sat, 25 Oct 2014 - 13:48

did you end up getting this to work?

#20 Sat, 25 Oct 2014 - 13:57

http://www.mouser.com/ProductDetail/Texas-Instruments/SN74HC166DRG4/?qs=sGAEpiMZZMtsbn1GaJysl2mUpBXeSqm3MB4LGbg4Gc4%3d

i am wondering if this will work.

36 ea cents for 10

Manufacturer: Texas Instruments Product Category: Counter Shift Registers RoHS:

Details Brand: Texas Instruments Counting Sequence: Serial/Parallel to Serial Number of Circuits: 1 Package / Case: SOIC-16 Logic Family: HC Logic Type: CMOS Number of Input Lines: 9 Propagation Delay Time: 150 ns, 30 ns, 26 ns Maximum Operating Temperature: + 85 C Minimum Operating Temperature: - 40 C Packaging: Reel Function: Shift Register Mounting Style: SMD/SMT Number of Output Lines: 1 Operating Supply Voltage: 5 V Series: SN74HC166 Factory Pack Quantity: 2500 Supply Voltage - Max: 6 V Supply Voltage - Min: 2 V Unit Weight: 0.004938 oz

#21 Sat, 25 Oct 2014 - 14:08

If TI really makes them, they'd hopefully be good quality.

#22 Sat, 25 Oct 2014 - 19:38

Still waiting for the chip ..

#23 Mon, 27 Oct 2014 - 23:47

Finally I changed that chip and the screen issue gets solved!
But my joy didn't last too much. After some reboots, system won't start up any longer. I get the blinking question mark... I checked hard disc cable but it's well plugged. What could be happened?

#24 Mon, 27 Oct 2014 - 23:55

hard drive took a shit. Common problem, especially if its a quantum.

#25 Tue, 28 Oct 2014 - 02:15

That video board is seriously the only thing that causes that to happen?? Guess I'd better hold on to that analog board I wrote off two years ago and try it with a different video board; I definitely have three or four extra video boards just sitting around from dead analog boards!!!

#26 Fri, 31 Oct 2014 - 07:43

ok cool this hc166 works out pretty good, ill run it for a couple days just to make sure.

#27 Fri, 31 Oct 2014 - 14:41

so the above post is re this part:

http://www.mouser.co...qm3MB4LGbg4Gc4=

i am wondering if this will work.

36 ea cents for 10

Manufacturer: Texas Instruments Product Category: Counter Shift Registers RoHS:

Details Brand: Texas Instruments Counting Sequence:Serial/Parallel to Serial Number of Circuits: 1 Package / Case: SOIC-16 Logic Family: HC Logic Type: CMOS Number of Input Lines: 9 Propagation Delay Time: 150 ns, 30 ns, 26 ns Maximum Operating Temperature: + 85 C Minimum Operating Temperature: - 40 C Packaging: Reel Function: Shift Register Mounting Style: SMD/SMT Number of Output Lines: 1 Operating Supply Voltage: 5 V Series: SN74HC166 Factory Pack Quantity: 2500 Supply Voltage - Max: 6 V Supply Voltage - Min: 2 V Unit Weight: 0.004938 oz

#28 Fri, 31 Oct 2014 - 14:48

In this case with my order of 10. I emailed orders@mouser.com

Told them to add 10 to my 1st class order that i had placed the day before. Because i knew it hadn't left yet anyway.

They said no they could not add it. But would send me these out first class on them.

so i paid my 3 and change and got here the same time as the other order.