Samsung Knew a Third Replacement Note 7 Caught Fire On Tuesday and Said Nothing (theverge.com)

If you had started to feel sympathetic for Samsung, or safer with the Note 7, its latest flagship smartphone, don't be. Another replacement Samsung Galaxy Note 7 has caught fire, making it three of such incident this week alone. Read how poorly Samsung has dealt with the situation, via The Verge: This one was owned by Michael Klering of Nicholasville, Kentucky. He told WKYT that he woke up at 4AM to find his bedroom filled with smoke and his phone on fire. Later in the day, he went to the hospital with acute bronchitis caused by smoke inhalation. "The phone is supposed to be the replacement, so you would have thought it would be safe," Klering told WKYT, saying that he had owned the replacement phone for a little more than a week. "It wasn't plugged in. It wasn't anything, it was just sitting there."The most unsettling part is that Samsung knew of Klering's phone, and didn't say anything.

Comments

Re: Samsung is starting to behave like Tesla

[geoskd]

Over here in facts-based land, the Note 7 has a MAX77838 keeping track of power.

The MAX77838 is a power management IC. It claims to have some other circuitry for battery management, but since MAXIMs website does not acknowledge that part number, we have no way of knowing what it really has or doesn't have. All outward appearances would suggest that it is a custom chip for Samsung (probably used in several of their product lines). Personally, I expect that the MAX77838 is similar to the MAX77829 (PMIC + single cell Lion charging circuit). This would make some sense since it looks like Samsung elected to use an external PMIC, and since they had to have one anyways, getting one that had the charging circuit built in would not be that big a deal. Unfortunately for Samsung, the charging circuit has to be relatively tuned to the specific battery being used. Generically designed Lion chargers have a habit of failing. (So much so that Tenma actually ships many of their battery chargers with a fireproof pouch to put the battery in while charging it...

This just goes to show how stupid Samsung is for designing it this way. Since the fault lies either with the Custom Maxim Chip, with the battery itself (or a mismatch between the two), Samsung has backed itself into a corner. They cannot just replace the defective Maxim Chip with an off the shelf component because there is no drop in replacement or they wouldn't have had Maxim build a custom chip in the first place. Nor can they simply change the battery easily, as the batteries are manufactured to spec as well.

If samsung had offloaded the charging and battery management control into software running on one of the processors in the phone, then they would likely have been able to fix the problem with a firmware update. Now, because they did not have the sense to do what everyone else is doing, they are fucked.

The best kept open secret in the Phone / Tablet world are the PSOC processors that are used extensively for all of the low level work in these devices. Cypress sells nearly as many processors as Broadcom, and nobody has ever heard of them. Their processors come with built in PMIC, Capacitive touch sense (which is why everyone started using them in the first place), and a host of other powerful features that reduce part count and unit cost. I have personally designed a half dozen devices that used them, two of which had battery charging circuits and charge control software. The irony is that the PSOC processors cost cost about $5 each and they are full featured processors while the Maxim ICs Cost more than that and are just a PMIC.

TLDR: Samsung is staffed by incompetent engineers. Its no wonder they have exploding phones, their engineers designed a phone with at least $5 more parts than they should have had, but skipped on the thermostat protection on the battery to save $0.50. If they used this same chip in the S5, then they lost more than 60 million dollars in excess unit cost in just the first three months of sales, and now with the S7, its going to cost them billions.