Urgent alert to MSX2/2+ owners: suicide capacitors on HIC-1 daughterboard

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By Grauw

Ascended (10063)

Grauw's picture

08-09-2017, 17:18

RetroTechie wrote:

Even among hardware hobbyists, few have such a tool. But what works equally well:

  • Take a sharp knife to the part, and cut through the solder itself (not the underlying pcb track!). Going 100% through isn't necessary as long as it's enough to pull the part from the board without taking pcb traces with it. This option has the advantage the pcb isn't heated at all, only when soldering in the replacement. Or
  • Use 2 soldering irons. Shocked! Most hobbyists have an old one lying around somewhere, or can borrow/buy a 2nd one for peanuts. A soldering iron on both sides of the part, and when solder on both sides has melted, you lift the part up like the Chinese grab rice with their eating sticks. LOL! Who cares where it drops or whether it sticks to the soldering iron - it's off the board, you discard it anyway, job done.

Thanks for the SMD desoldering tips.

I was thinking to add some fresh tin and then use solder braid / wick, wouldn’t that work as well?

By Alexey

Guardian (3204)

Alexey's picture

08-09-2017, 18:45

There's nothing better for desoldering of SMDs than this baby:

https://www.aliexpress.com/item/2015-Brand-NEW-Hot-858D-220V...

By sd_snatcher

Prophet (3471)

sd_snatcher's picture

08-09-2017, 23:06

Grauw wrote:

Thanks for the SMD desoldering tips.

I was thinking to add some fresh tin and then use solder braid / wick, wouldn’t that work as well?

If you have in mind the resistors and capacitors for the audio fix, then it's enough to heat one side of the part with the soldering iron, and after some time alternate to the opposite side. After you do this some 3 or 4 times the part will come loose and stick to the tip of the soldering iron, or at least slide out of the pads.

By sd_snatcher

Prophet (3471)

sd_snatcher's picture

09-09-2017, 13:44

I found a good video that shows how to easily desolder SMD resistors and ceramic capacitors.

And here how to remove the SMD electrolytic capacitors.

I hope it helps. :)

By Grauw

Ascended (10063)

Grauw's picture

09-09-2017, 15:03

Thanks!

I need to get off my ass and order those components already Big smile. Stupid free shipping threshold makes me want to look up more components to order.

By sd_snatcher

Prophet (3471)

sd_snatcher's picture

09-09-2017, 18:01

Another tip: when soldering the components back be sure to throughout fully clean the pads and the PCB around with isopropyl alcohol and a cotton swab, then apply a good solder flux on the pads. Here's a SMD resistor soldering.

By joseph0126

Supporter (12)

joseph0126's picture

01-08-2019, 10:37

Hi Folks, today I replaced 3 capacitors on HIC-1 daughter board with Tantalum capacitors, C10=10uf/16v, C14=10uf/16v, C22=100uf/16v, my console is Sony HB-F1XD, the startup screen display abnormal like below, there are several noise on the left area, and the noise will almost disappear after 10 mins. Did I use the wrong specification of capacitor ? Please advise and Thanks a lot. Smile

image

By dublevay

Supporter (14)

dublevay's picture

05-09-2020, 18:44

A few weeks ago I received my first MSX machine from Japan via Jauce. It's a Sony HB-F1XV.

I'd read this post and decided that I would need to replace these capacitors, but by crikey, what a mess I got into. Because I wanted to be careful and not pull up any SMD pads I decided remove the electrolytics using hot air. I must have had too much air flow, as I ended up also blowing away three resistors - 820R, 1K and 0R.

Anyway - much rework later, all of the resistors were back in place, and the decent quality Kemet tantalums were soldered in - with the band on the component aligning to the positive marking on the board - i.e. I know that tantalums have the +ve marked unlike electrolytics which have the -ve marked.

I booted the machine and got absolutely no video output from composite or RF - and after building an RGB cable, discovered I was getting nothing out of that either. Audio was getting through, and I was able to ensure that the machine was working using PLAY "AA".

I traced much of circuit according to a schematic I found for the HIC-1 online and decided that everything was OK - but still no output. At this point I decided it had to be down to the tantalums, and so ordered some high-quality Panasonic 10uF (HD type) and 100uF (HC type) SMD electrolytics. The 100uF is actually a 6.3V part - as was the original, which was marked 6A. The 10uF was originally 16V, and I again went with that rating. This was mainly to match the original component sizes.

So the new parts arrived and I carefully fitted them. Switched on and I still had no decent RF or composite - but it did randomly flick up a coloured display fleetingly. I did now have excellent RGB however. After much searching through the CXA1145 spec and looking at the HIC-1 schematic I decided that the area of concern had to be between pins 16 and 18, where the C-SYNC is added back in for the composite signal. This was because I could see the colour display fleetingly, so chroma was obviously present.

After some rather intricate multimeter buzzing out of the circuit around there, I worked out that the 22uH inductor was not connected properly - despite it's pad on the PCB being connected, and the solder joint looking more than adequate. So I reflowed both ends with some decent solder, reassembled - and lo and behold, everything working again.

Many many lessons learned here. It would be easy for me to blame the tantalum capacitors - but with hindsight, now that I've seen just how easy a dodgy joint is to encounter with SMD, then it could well have been bad joints on those tantalums anyway.

It's all sorted - and to be honest, the finished result with the electrolytics looks better than the tantalums did - and I also found the electrolytics easier to fit as well.

Before image:

After image (ignore the missing 0R resistor - that was added back in!):

By Pac

Guardian (6396)

Pac's picture

05-09-2020, 19:23

Thank you for letting us know this issue and good to know you finally solved the problem. I guess that coil is also located on HIC board right? What a bad time when our MSX doesn't work after a simple repair... LOL!

By dublevay

Supporter (14)

dublevay's picture

05-09-2020, 20:20

Yes, it's the 22uH inductor just below the lower 10uF cap (marked 220). The black component.

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