From the pics, the board seems to have at least three voltage regulator circuits.
The transistor that's blown seems to have some heat sinking (there are a few vias visible in sim's pic around the device. If thay are just for this transistor, then that can help narrow the search a bit.
Are there components on both sides?
Can you provide some better macro photos of the board that shows the traces and the top marks of the devices in that area?
Is the black connector a power connector?
replacing the transistor with two 1N4148 Dioni find 24 volts on the anode of a diode and 12 volts on the anode of the other diode. but to pin 7 V in the LM2672 can not find tension.
My Q1 looks exactly the same as yours issic. The right side is blown off. What's left reads H6F and a partial U so I'm guess it's the H6FU9 that kkmanuele mentioned.
All I've been able to find is this information on H6:
Device = BCW89R
Manufacturer = Phi (Phillips)
Base = R (?)
Package = SOT23R
The 3rd char is F which refers to this:
. |D| . . . |S| (ignore the spacing dots)
What does the U9 refer to? Any clues what replacement part I need?
CFD 1081/1082 Transistor Q1
The thread i9s somewhat outdated, but I think there are many questions left.
I found this for Q1:
There are several codes referred here to Q1 like:
I think that only the first two letters are signicant together with the package
(SOT-23 or 2.9 x 1.5 mm).
H6 should be a pnp-Transistor like BCW89R, but Q1 is not pnp.
HE may be a npn-transistor 2SC3123 or 2SC4250 (Toshiba).
HF is similar 2SC3124 (Toshiba)
The three following letters ar not significant.
I think this information may help someone out there.
Vielen Dank, Herr risck. I think I have to add the ID of my "Q1" to the list: HEZ H4 According to this link, H4 is: a BCW69R, a BC177A equivalent in a SOT23R package. H6 is: a BCW89R, a BC556 equivalent, also in a SOT23R package. Both the BC177A and the BC556 come in a TO-92 package.
I believe a 2N4403 will do also, but please do check the specsheets! SOT23 equivalent of this reads 2T.
Both H4 and H6 are PNP, but in a reversed package. Could this be the reason for your remark
Whichever equivalent you use, be very sure to mind the difference in pinout for the different packages!
Anyhow, I will be acting on these specs presently and post the results ASAP.
Thanks again for your post!
Welovemacs has this board…
0171-2242-1471 20" & 23" Apple Aluminum Cinema Display Main Inverter Board
It claims to be an inverter board, but the picture is the main board, worth confirming if you are interested in getting the entire board.
issic's old ebay link had a few main boards on sale…
Apple | eBay
I have this bad picture I took when I fixed a different LDO on a friends 23" ACD…
I can't identify the ic from the picture, sorry.
I have a working 23" display but I haven't opened it at all, I don't know if it would actually help to have another pic of the component? Isn't the main problem identifying the part from the info printed on it?
I guess I could put a meter across it to see what it's operating voltage is but is everyone sure what type of component it is?
I don't really want to short out an unknown component in a working display.
Thanks, Drew! Just so you know: I am very intrigued by this ACD issue, and by sheer stubbornness I've been at mine all day. Not that I am really in need of a 20" or 22" lcd display, I just want to know.
I do not really want to spend more money on it (only spent 30€ in the first place), I just want to get the component level repair done properly, and in doing so, maybe find out what is bugging such an awful lot of these machines.
The issue right now is the pinout for SOT 23R: on the Net, e.g. there seem to be circulating faulty pinouts in different locations. Whereas the right one, I think is just the mirror image of the SOT 23 (confirmed by this quote:
Please do not harm any component in a working display on my account! I am just experimenting with a faulty display mainly out of curiosity. With an eventual bonus of having a working specimen, of course.
A pretty good picture of the whereabouts of Q1 in question have already been posted earlier in this thread.
Anyhow, thanks an awful lot for your kind cooperation! I intend to get to the bottom of this, but do not follow my folly if you have a regular dayjob!
On my board "Q1" is "HEXS5" and definetely not a reverse package, since the leads are near the board.
Sorry for my persistance, but given these specs of the2SC3123:
and seeing one of its contacts are connected directly to the 24.675 V of the powerbrick, I think it should immediately blow up. Or am I completely mistaken?
Also, the form factor does not seem right.
Moreover, why am I unable to locate any HE or HF types in different SMD codebooks?
Great thanks for thinking along, BTW!
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