Login Join Maker Pro

# What is this? Does it look fried?

#### petedw

Apr 17, 2010
6
I'm trying to fix my a/c unit in my car. It has a digital display. I think this part if fried and I'm trying to figure out what it is.

#### Attachments

• IMG_2100.JPG
23.8 KB · Views: 290

#### Externet

Aug 24, 2009
830
Both the PNP transistor and the 100? Ohm resistor seem fried.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
The transistor or the resistor? The resistor looks like it's been pretty hot.

Is there any particular reason you suspect these parts?

edit: Externet -- why do you think the transistor is fried, and how do you pick it for PNP. I can't decipher a part number (or at least one I can locate). The stuff on the tab of the transistor looks to me like it's from whatever is being used to prevent the nut from shaking loose.

Last edited:

#### petedw

Apr 17, 2010
6
Resistor common problem

People say that the resistor works as a fuse on these units and burns up when other things are bad. I changed out my resistor with some capacitors, but unit started smoking. Resistor was frying again and I just happened to notice how how that (transistor?) was and did not remember the black stuff on top of it. Is there a way to test it and do the numbers on top mean anything? They are .T B1019 Y 1A. Thanks for any help.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
I'm sure the numbers mean something, but I'm afraid they look like the manufacturer's internal part numbers. They get them with "special" markings with the side effect of making the device harder to service by people without the knowledge of what this translated to.

If the black stuff on the transistor looks and feels like the stuff keeping the nut secured, then it's probable that you simply failed to notice it.

The device it marked on the board as a transistor, so it probably is What sort is another question...

You said you replaced the resistor (and it looks like it). Are you sure you replaced it with the same value? You seem to have discussed this problem with other people. Do any of them know what type of transistor it is? I don't suppose you have a circuit diagram for this?

#### petedw

Apr 17, 2010
6
Oh, yes it is marked as a T on the board for transistor. Thanks, I don't really know what I am doing, but am hopefully learning. Many others on the auto forum I have been reading changed the resistor and used the one I used (1ohm 1watt). Unfortunately no one has a circuit diagram. The black stuff feels hard and I feel like when I zoom into a picture that it may be burned plastic, but can't be sure. Is there anyway to determine what I would need to replace it with?

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Firstly it would be useful to know if the correct value is 1 ohm.

Secondly it would be useful to know what transistor people have replaced this with *and* have got it working again.

If the substance comes off with a little prodding and looks like carbon (from the epoxy most likely) then it's a bad sign. See if there's a short across any pair of the leads of the transistor. Note that components in the circuit may have a low resistance, so this is not definite.

Last edited:

#### petedw

Apr 17, 2010
6
I know that the resistor is the correct one. I have not found anyone who has replaced the transistor. There is no short between the leads, but the stuff chips off and has the same color to it as the transistor itself. Is there any hope for finding a proper replacement?

#### Resqueline

Jul 31, 2009
2,848
The transistor is made by Toshiba and is a 2SB1019. This seems like it could be part of a switchmode inverter circuit by the look of the toroid beside the transistor.
The "oozing" stuff may simply be blackened glue used to fix the nut. The transistor need not be damaged even if it's been hot.
Can you post a bigger & more overlooking picture, and also of the backside of the board, so that we may have a chance of "dechiphering" the circuit?

Apr 17, 2010
6

#### Externet

Aug 24, 2009
830
...edit: Externet -- why do you think the transistor is fried, and how do you pick it for PNP. I can't decipher a part number (or at least one I can locate). The stuff on the tab of the transistor looks to me like it's from whatever is being used to prevent the nut from shaking loose.

Transistors starting A,B are abreviated from 2SA, 2SB and are PNP. Transistors starting with C, D are abbreviated from 2SC, 2SD which are NPN. Japanese 'save ink' stamping them that way.

The resistor is a flameproof type to prevent fires on obviously fire prone circuits; it may be in series to such transistor, which means the transistor shorted and passed overcurrent to the resistor, so both are suspected fried.
The reason why the transistor fried first has to be investigated, as what does it drive/supply power to. (a solenoid? A fan?) And fixed first. As just replacing them will let the smoke escape again.

Edited: added---> Looking at the pictures, Seems that transistor upconverts 12V to ~ 200VAC for the display operation.

Jerry G.

#### petedw

Apr 17, 2010
6
Thanks

Thank you. You all have been very helpful

#### Tesla

May 10, 2010
165
This wouldn't happen to be for a 2004 Honda Accord would it ?

#### warged

Apr 29, 2010
1
Yes and the resistor also

#### Tesla

May 10, 2010
165
This wouldn't happen to be for a 2004 Honda Accord would it ?

Nevermind ... I found the large dropbox pictures and I see that it is not.

I'll just add that the 2004 Honda Accord has a similar problem on the Climate Control/Radio display board. It's pretty easy to fix yourself if you are handy. However, many Honda dealers will replace the unit for free, even if you are out of warranty
(goodwill repair).

L
Replies
3
Views
3K
Mark D. Zacharias
M
Replies
6
Views
198
Replies
8
Views
271
Replies
4
Views
394
Replies
6
Views
521