help identifying a capacitor on a Rollei Hy6

[mattlock]

This virus had my digging up my old cameras so I took out my Hy6, loaded up the battery and 80mm lens, turned it on and autofocused, then heard a "pop!" and a burst of black smoke.

Sigh
So I've two options here- send it to germany for repairs which would probably be difficult due to lockdown restrictions in my country
or fix the faulty part, which based on my experience, wouldn't be too much trouble.

Popped open the handle and sure enough, a nice blown component. I suspect it's an SMD capacitor and it's probably easy to replace, if I actually knew what the rating on this capacitor was.

Trying my luck here, does any Hy6 owner have any spare board lying around which they could use to measure the capacitance of this component? (praying for a miracle...)

thanks in advance!

 

[spijker]

Maybe try contacting DW-Photo:
https://www.dw-photo.eu/service.html

I recently saw a short German TV documentary on them. It seems to be a nice and dedicated group of people running what's left of the original Rollei. Given the circumstances they might be willing to look up the value/voltage of that capacitor so you can replace it yourself.

 

[mattlock]

Maybe try contacting DW-Photo:
https://www.dw-photo.eu/service.html

I recently saw a short German TV documentary on them. It seems to be a nice and dedicated group of people running what's left of the original Rollei. Given the circumstances they might be willing to look up the value/voltage of that capacitor so you can replace it yourself.

I actually did contact them...they weren't willing to share with me the value of the capacitor..I guess they were afraid it would cause more problems if I do so. But shipping it out to germany is probably tough during this period as we're under lockdown for another month

 

[DBF]

Try to read what is written on the (black) integrated Circuit next to the Capacitor and look for Datasheet of it.
Maybe they use a Standard - Application of this Part.

 

[mattlock]

Try to read what is written on the (black) integrated Circuit next to the Capacitor and look for Datasheet of it.
Maybe they use a Standard - Application of this Part.

hey thanks for that suggestion, it was actually really smart! I didn't think about that.

too bad I couldn't find any info on the IC- the letters on it is 74TI BFM
my first thought was that it was a Texas Instruments IC but couldn't find anything like that online.

 

[buildbot]

hey thanks for that suggestion, it was actually really smart! I didn't think about that.

too bad I couldn't find any info on the IC- the letters on it is 74TI BFM
my first thought was that it was a Texas Instruments IC but couldn't find anything like that online.

Are there any other markings on the chip? 74 is a really common series of TTL logic chips, but this looks like some kind of power IC or maybe an amplifier. TI makes an op-amp called a 741? The circuit looks like an RC setup with an inductor, which really seems like a power circuit to me.

Caveat - I'm on the digital side of EE, so I'm just guessing based of college circuits courses long ago.

 

[mattlock]

Are there any other markings on the chip? 74 is a really common series of TTL logic chips, but this looks like some kind of power IC or maybe an amplifier. TI makes an op-amp called a 741? The circuit looks like an RC setup with an inductor, which really seems like a power circuit to me.

Caveat - I'm on the digital side of EE, so I'm just guessing based of college circuits courses long ago.

you guys are absolutely amazing. I assumed it was a capacitor because of the way it "popped" and the black smoke- but I have no experience with power IC/amplifiers so I did not consider it.
Do share more of your insight, I Really really appreciate i!
not sure if this helps but The underside of the PCB has a NXP LPC2148

 

[MartinN]

I have had components burn in different electronics, sometimes capacitors and sometimes other components. Unfortunately it is not always so straightforward to replace only the burned components, you need to know why it happened. Overvoltage could be one cause, but then you have to know why there was overvoltage. Mostly my electronic devices ended up in landfill because they vere largely destroyed by overvoltage. Don't know anything for certain.

 

[spijker]

The 10-pin 74TI BFM IC is probably a switching voltage regulator/converter since there's an inductor and some transistors on the other side of the PCB. Probably supplying the NXP microprocessor with the right voltage. If that is the case, then there's a good chance that the same circuit is used on other PCBs in the camera. See if you can find a 74TI BFM on another PCB and find out what the popped component is.

 

[mattlock]

I have had components burn in different electronics, sometimes capacitors and sometimes other components. Unfortunately it is not always so straightforward to replace only the burned components, you need to know why it happened. Overvoltage could be one cause, but then you have to know why there was overvoltage. Mostly my electronic devices ended up in landfill because they vere largely destroyed by overvoltage. Don't know anything for certain.

when I called DHW, they asked about the Lens.
I actually fired off shots with this camera using my standard PQ lenses without problems , but when I put on the 80mm AF PQS lens, that's when this happened.
It's likely related to the autofocus. but it's ok because I don't intend to use the autofocus.

I'd really like to fix this because the Rollei has special meaning for me, some of my best personal photos were shot using rollei lenses. so I'll regret it if I don't at least try to fix it

I'm actually also waiting for some of our engineering interns to come onboard so I can try to make a Hasselblad mount to Rollei adapter...we've established we can trigger the back using a sync cord.

 

[MartinN]

Of course there are a lot of good camera repair facilities and a capacitor and AF problem may be very easy to repair. The devices I have had to discard were AC powered devices and the power supply system had burned a great deal and nobody was interested in repairing those cost effectively.

 

[mattlock]

The 10-pin 74TI BFM IC is probably a switching voltage regulator/converter since there's an inductor and some transistors on the other side of the PCB. Probably supplying the NXP microprocessor with the right voltage. If that is the case, then there's a good chance that the same circuit is used on other PCBs in the camera. See if you can find a 74TI BFM on another PCB and find out what the popped component is.

there's another board it connects to but it's not present on it.I do see some PCBs hidden on the left and right side of the mirror box but I don't think I can access that area (also abit cautious about opening up the camera any further due to potentially screwing up some of the mechanisms inside)

Based on what you're saying, if it's a switching voltage regulator/converter, do you have any clue on how to identify the component?

 

[mattlock]

Of course there are a lot of good camera repair facilities and a capacitor and AF problem may be very easy to repair. The devices I have had to discard were AC powered devices and the power supply system had burned a great deal and nobody was interested in repairing those cost effectively.

my guess was capacitor, based on the fact that the AF was jamming abit before the pop and burning smell happened.
The problem now is just about how to identify the correct capacitor to try... and also ensuring the spoilt part inside is a capacitor and not some other component

 

[DBF]

It is a Switching Voltage-Regulator. It makes the Voltage independent from the Battery-Voltage - I am 99% sure.
The Value of the Capacitor is not so critical - 22 Mikrofarads and 16 Volts should be good.
But must find out the Polarity.

 

[mattlock]

It is a Switching Voltage-Regulator. It makes the Voltage independent from the Battery-Voltage - I am 99% sure.
The Value of the Capacitor is not so critical - 22 Mikrofarads and 16 Volts should be good.
But must find out the Polarity.

based on your input, I went to look up abit more on buck converters and realised the circuit looks similar. However I can't find an equivalent on the blown component on a standard buck converter. Your'e saying it's a Switching Voltage-regulator?

Is there a way for me to check the polarity with a multimeter?

 

[mattlock]

UPDATE:

I did abit more digging on a buck converter, and realised there are diodes that look similar?
Any possibility the blown component is actually a diode?

 

[DBF]

You should measure with a Multimeter (set to Ohm / Resistance), if there is a direct Connection (close to Zero Ohms) from from the Metal-Part of the Socket (in Your First Photo Bottom / left - soldered with four big Solderpads to the PCB) to one of the Solder-Pads of the burnt Capacitor.
If there is - that Solderpad is Minus.

 

[JonathanP]

I think the switching regulator may be a TI TPS62050 (http://www.ti.com/lit/ds/slvs432d/slvs432d.pdf) because TI use 3 character marking and this one is a "BFM":



It's also a 10 pin package and the output range is plausable for this type of application. The standard reference circuit looks similar:



This backs up DBF's recommendation of a 22uF capacitor. You could use a multimeter to see if it looks like the capacitor and inductor are connected to the same pins to get extra confidence this is the chip.

Hope that helps,
Jonathan

 

[JonathanP]

Actually, looking carefully at your photo of the board, I'm not convinced the blown component is the 22uF output capacitor. I can see that the inductor is connected to pin 9 of the chip and I think the 22uF may be the capacitor above the inductor in your photo.

So I think you may need to do a little tracing of the connections to see exactly where that is connected, but hopefully this has helped a little.

Jonathan

 

[mattlock]

I think the switching regulator may be a TI TPS62050 (http://www.ti.com/lit/ds/slvs432d/slvs432d.pdf) because TI use 3 character marking and this one is a "BFM":

View attachment 149194

It's also a 10 pin package and the output range is plausable for this type of application. The standard reference circuit looks similar:

View attachment 149196

This backs up DBF's recommendation of a 22uF capacitor. You could use a multimeter to see if it looks like the capacitor and inductor are connected to the same pins to get extra confidence this is the chip.

Hope that helps,
Jonathan

this is super useful. you're a real detective.
So the Inductor is the square component with the 100 marking correct? and the capacitors are the rectangular components surrounding it. the blown component is the one I circled, any insight on what they may be based on the diagram?